Developing Operational Model for Heat Pumps as Space Heating and Domestic Hot Water Provider

In the United Kingdom, means of meeting domestic heating is being electrified to decarbonise in effort to reduce the greenhouse gases emissions from the burning of natural gas. Therefore, the uptake of heat pumps is on the increase. The operation and working principle of heat pumps must be well understood in the investigations of their impacts on the grid and the grid assets, especially distribution transformers which could be overloaded due to higher peak load demand. This work develops an operational model of heat pumps as combined space heating and domestic hot water provider implemented in MATLAB. The developed operational model of heat pumps is adaptable and repeatable for different input parameters. The developed model is used to generate daily average demand profiles of heat pumps for a typical winter weekday and a typical summer weekday. The generated demand profiles of heat pumps by the developed model compared well with the demand profiles of heat pumps generated from actual field projects which are usually expensive and time-tasking.

A Lightweight Electronic Water Pump Shell Defect Detection Method Based on Improved YOLOv5s

For surface defects in electronic water pump shells,the manual detection efficiency is low,prone to misdetection and leak detection,and encounters problems,such as uncertainty.To improve the speed and accuracy of surface defect detection,a lightweight detection method based on an improved YOLOv5s method is proposed to replace the traditional manual detection methods.In this method,the MobileNetV3 module replaces the backbone network of YOLOv5s,depth-separable convolution is introduced,the parameters and calculations are reduced,and CIoU_Loss is used as the loss function of the boundary box regression to improve its detection accuracy.A dataset of electronic pump shell defects is established,and the performance of the improved method is evaluated by comparing it with that of the original method.The results show that the parameters and FLOPs are reduced by 49.83%and 61.59%,respectively,compared with the original YOLOv5s model,and the detection accuracy is improved by 1.74%,which is an indication of the superiority of the improved method.To further verify the universality of the improved method,it is compared with the results using the original method on the PASCALVOC2007 dataset,which verifies that it yields better performance.In summary,the improved lightweight method can be used for the real-time detection of electronic water pump shell defects.

Development and Experimental Study of Air Source Heat Pump Water Heater

The principle and development prospect of air source heat pump water heat were introduced,as well as the designation of condenser (storage water tank),experimental study on installations was also carried out.The results showed that air source heat pump water heater was superior to conventional system.Under the operation of cooling and heating,heat pump comprehensive utilization equipment could improve heating performance,reduce energy consumption,and recycle condensing heat to provide hot water.

Experimental study on characteristics of transcritical heat pump water heater using refrigerant HFC125

To evaluate the performance of heat pumps using refrigerant HFC125,an experimental rig of a DC-inverter heat pump water heater is designed and set up,and the research on the transcritical heat pump water heater is carried out experimentally.It is found that there is a top value of the coefficient of performance（COP）when the system runs at 95 Hz of frequency.The relationships between the COP and compressor frequency,condensation pressure,evaporation pressure,condensation water temperature rise,and discharge temperature are discussed and analyzed at 95 Hz.And the COP of the HFC125 transcritical cycle is also compared with that of a R410 subcritical heat pump under the same conditions.The results indicate that there exists an optimum frequency for a better COP,and the system COP shows an increasing tendency with the decrease in condensation pressure and compressor ratio while the evaporation pressure remains invariant,and the COP decreases rapidly when cooling water temperature rises over 47.5 ℃.Compared with the R410A sub-critical cycle,the COP of HFC125 transcritical cycle significantly increases by 12% on average.

Influence of Valve's Characteristic on Total Performance of Three Cylinders Internal Combustion Water Pump

Intenal combustion pump （ICP） is a new type power device turning the thermal energy from fuel combustion into fluid pressure energy. Three cylinders prototype has just been developed. The study on the influence of valve＇s characteristic on ICP＇s total performance will found the base for its optimum design. Based on the theoretical and testing fruits of single cylinder prototype, the performance of the valves and complete appliance of the latest is simulated. When the natural frequency of valves is approximately to the round number times of the working frequency, volumetric efficiency is seriously low. The nominal rotational speed of the prototype is nearly to the speed where the volumetric efficiency is lowest, which is harmful to the normal work of ICP, so further structure optimization of valves should be carried out. The change of volumetric efficiency has great influence on the fuel consumption rate, output flow, effective thermal efficiency, effective power, and so on, but little on output pressure.

Experimental Study of Thermoelectric Heat Pump Water Heater with Exhaust Heat Recovery from Kitchens

A new kind of thermoelectric heat pump water heater for kitchens exhaust heat recovery was presented,and its performances were investigated under different operating voltages.The experiment results show that the coefficient of performance decreases and the temperature difference between the hot and cold sides becomes larger with the increase of the operating voltage,but the heating time becomes short.The higher the temperature of water,the greater the temperature difference between the hot and cold sides,leading to a smaller coefficient of performance.Under an exhaust temperature of 36 ℃,the coefficient of performance decreases from 1.66 to 1.22 when the temperature of water increases from 28 ℃ to 46 ℃ with operating voltage 16 V.Performance tests illustrate that,compared with the conventional electrical water heaters,the new kind of thermoelectric heat pump water heater is more coefficient.

Optimal Operation for Baoying Pumping Station in East Route Project of South-to-North Water Transfer

Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes （namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge）, the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge.

Pressure fluctuation and its influencing factors in circulating water pump

In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.

DYNAMICS MODEL AND SIMULATION OF FLAT VALVE SYSTEM OF INTERNAL COMBUSTION WATER PUMP

The dynamics differential equations are constructed, and the initial conditions are also given. Simulation shows the following conclusions： The water pressure in cylinder has great instantaneous pulsation and phase step when outlet valve or inlet valve opens, but is more gently in other time; The volume efficiency is influenced by the output pressure slightly, and decreases as the working rotational speed increases; When the inherent frequency of the valves is integer multiple of the working frequency, the volume efficiency of system will decrease evidently.

Studies on the changes of West Lake＇s zoobenthic communites after Qiantang River water was pumped into it

During Jan.1995 to Dec.1996, monthly investigations on the zoobenthic communities of West Lake, samples were collected from six sampling stations. A total of 26 species of macrozoobenthos were identified. The seasonal changes in density and biomass of zoobenthos in this lake were analyzed. The annual mean densities were 980～2751 ind/m\+2 and mean biomass was 19.69-122.80 g/m\+2. The densities in winter and early spring were higher than those in summer and autumn. Comparative study of theprevious data (1982 to 1983) collected by the authors, showed that the succession of zoobenthic communities, dominated by \%Procludius choreus\% in density and \%Bellamya purificata\% in biomass, had been occurred in Xiaonan sub\|lake after Qiantang River water was drawn into it; and that the species and biomass of zoobenthos were then increased and the density was decreased. In other sub\|lakes, the dominant species were \%Limnodrilus hoffmeisteri\% and \%Tokunagayusurika akamusi \%in density and \%Branchiura sowerbyi\% and \%Tokunagayusurika akamusi \%in biomass. The water quality was bad in these sub\|lakes because these dominant species are indicators of eutrophication. According to the Margalef index and Goodnight index, West Lake is still an eutrophic lake. Only the water quality of Xiaonan sub\|lake was improved after water drawn from the Qiantang River was introduced into it.

Seepage effects of groundwater and its make-up water on triggering ground subsidence

The functioning mechanism of groundwater and its make-up water in the process of ground subsidence was studied from such three aspects as osmotic corrasion, osmotic pressure effect and concretion effect, As to osmotic corrasion, its forming conditions, mechanical mechanism and process were analyzed, As to osmotic pressure effect, it was mainly studied from hydrostatic pressurizing effect, sop softening effect and negative pressure sealing effect. Through concretion and saturation of soil, the factors of concretion settlement were analyzed. The results showed that both groundwater and its make-up water are important triggering factors to ground subsidence.

Experimental assessment of two-phase bubble pump for solar water heating

The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat could be transferred downward from the collector to a hot water storage tank.The designed system consists of two sets of heat-pipe evacuated tube collectors,a solar bubble pump installed at an upper level and a water storage tank with a heat exchanger at a lower level.Discharge heads of 1 and 5 m were tested.The bubble pump could operate at the collector temperature of about 90-100 ℃ and vapor gage pressure of 80-90 kPa.It is found that water circulation within the SWHS depends on the incident solar intensity and system discharge head.Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly,daily and long-term performance tests.The thermal performance of the proposed system is compared with conventional solar water heaters.The results show that the proposed system achieves system characteristic efficiency of 10% higher than that of the conventional systems using electric pump if taking the consumption of electric power into account.And the former is a zero carbon system.

Lubrication and tribology in seawater hydraulic piston pump

Water hydraulic systems have provoked major interest because of the human friendly and environmental safety aspects. Piston pump is one of the most frequently used hydraulic units in recent engineering technique. In water hydraulic piston pump, poor lubrication is more likely to happen than in oil hydraulic one because of difference in properties between water and oil. So there are some key problems such as corrosive wear and erosion, which are investigated briefly. Many new materials have been developed, which give longer life expectancies with water without corrosion and erosion. A new type of seawater hydraulic piston pumps with better suction characteristics had been developed at HUST. Much of this research has concentrated on new materials, structure and experiments, which are also specially introduced.

Feasibility Analysis of Back-Pressure Steam Feeding Water Pump for Direct Air-Cooled Unit

As the performance of an air-cooled condenser is apt to be affected by the fluctuating ambient condition, some difficulties are brought to the use of a steam feeding water pump in an air-cooled unit. This paper introduces a new design of for steam feeding the water pump of an air-cooled unit using the back-pressure steam turbine as the prime motor. Using variable condition analysis on a 600 MW direct air-cooled unit, and with consideration of the effect on the ambient conditions, the feasibility, economy, and adaptability of the design are verified.

Automatic Control of Water Pumping Stations

Automatic Control of pumps is an interesting proposal to operate water pumping stations among many kinds of water pumping stations according to their functions.In this paper,our pumping station is being used for water supply system. This paper is to introduce the idea of pump controller and the important factors that must be considering when we want to design automatic control system of water pumping stations. Then the automatic control circuit with the function of all components will be introduced.

Study on corrosion behavior of heat exchanger in water source heat pump

Water source heat pump is a new kind of energy saving process.One of the most common problems for water source heat pump system is the corrosion of the copper in heat exchanger.The quality of water is the key factor.The river water collected in six different places of the Yangtze River and Jialing River in Chongqing were analyzed.Various parameters(pH,coexisted ions,and hardness value)were investigated.It showed that the Yangtze River and Jialing River water was suitable for developing water source heat pump technology.Further more,aimed at the temperature and pH of the raw water's variation range in a year,the corrosion behavior of copper material was studied by controlling the water environmental condition.Corrosion rate of copper is accelerated at high temperature and lower pH value.

Design on Vibration Monitoring and Fault Diagnosis System of Large Water Pump Motor

Large water pump motor,whose operation decides the reliability of the whole production line,plays a very important role.Therefore,its online condition monitoring can help companies better know its operation,process fault analysis and protection.The essay mainly studies and designs large water pump motor′s real time vibration monitoring and fault diagnosis system.The essay completes the systems project design,the establishment of the system and performance test.Eddy-currentsensor,XM-120 vibration module,XM-320 axial translation module,XM-362 temperature module,XM-360 process amount module and XM-500 gateway module are used to measure the axial vibration and displacement of main motors.Laboratory tests prove that the system can meet the requirements of motor vibration monitoring.

Dynamic Modelling of Submersible Pump Based Solar Water-Pumping System with Three-Phase Induction Motor Using MATLAB

The main purpose of this paper is to design and model a water-pumping system using a submersible multi-stage centrifugal pump driven by a three-phase induction motor. The system is intended for pumping water to the surface from a deep well using three power supply systems: a general network, a photo-voltaic (PV) system, and a PV system with a battery bank. These systems are used to compare two three-phase induction motors—namely, a motor with a drive and another one without a drive. The systems dynamic models are simulated in MATLAB/Simulink and the results compared with the manufacturer’s data for validation purposes. The simulation results generally show system dynamics and expected performance over a range of operation.

Design and Performance of Photovoltaic Water Pumping Systems: Comprehensive Review towards a Renewable Strategy for Mozambique

The use of solar photovoltaic (PV) technology for water pumping systems (WPS) has been one of the most popular forms of solar energy application in recent decades in remote and desert areas, as well as in some urban areas. In this article, an advanced literature review on the design and performance of solar technology for water pumping is presented, exploring also the best perspective of transition for the developing countries energy needs. Additionally, this paper intends to analyze the Mozambique’s perspective on renewable energy technologies setting the Mozambican scenario regarding photovoltaic water pumping systems (PVWPS) technology with the aim to identifying the main knowledge of PVWPS design and research gap. The results show that the most commonly used configuration of PVWPS technology is direct coupling systems without battery storage. These systems are simple and reliable, mainly used in small-scale pumping for small irrigations and domestic use. The mainly variables that influence the performance of PVWPS are: total dynamic head, quantity of fluid extracted, variation of solar radiation level, PV and motor pump technology. Yet, the efficiency of the PV and overall system does not exceed 10% and 5%, respectively. Looking at the designing, mathematical models, software-assisted is being predominant. Yet, as research gap, it is possible to understand from different authors that the dynamic nature of the end-use of PVWPS is not explored on methodology design of PVWPS, and the techno-economic optimum system configuration is not always the one that gives the highest annual system efficiency. For the Mozambican’s context, PVWPS for irrigation has been expanding slowly but has gained expression since 2013. In turn, static models based on software of pump manufacturers for PVWPS design are the most widely used in Mozam-bique. In Mozambique, PVWPS match the perspective of different researchers regarding the availability of solar resource, boreholes and amount of water required for irrigation. The adoption of PVWPS is a means of increasing the sustainability of the rural communities.

Determining safe yield and mapping water level zoning in groundwater resources of the Neishabour Plain

Groundwater is a crucial sources of water supply,especially in arid and semi-arid areas around the world.With uncontrolled withdrawals and limited availability of these resources,it is essential to determine the safe yield of these valuable resources.The Hill method approach was used in this study to determine the safe yield the Neishabour aquifer in Khorasan Razvi province in Iran.The results showed that the safe yield in the Neishabour aquifer is 60%lower than the current pumping amounts during the study period,indicating that further overdrafts could result in the destruction of this aquifer.This highlights the importance of using the Hill method to estimate the permitted exploitation from other aquifers,thus preventing problems caused by over-extraction and maintaining stability of global groundwater levels.